Flame retardant dust control fabric

ABSTRACT

EMULSIFIABLE FLAME RETARDING COMPOSITIONS FOR PREPARING DUST CONTROL FABRICS ARE DISCLOSED. THE COMPOSITIONS COMPRISE AN OIL HAVING A FLASH POINT ABOVE ABOUT 150*C., A FLAME RETARDING ORGANIC PHOSPHATE ESTER AND EMULSIFYING AGENT. THESE COMPOSITIONS READILY FORM AQUEOUS EMULSIONS FROM WHICH THE OIL COMPOSITION IS EXHAUSTED ONTO DUST CONTROL FABRICS SUCH AS CLOTHS AND MOPS. SUCH TREATED DUST CONTROL FABRICS EXHIBIT IMPROVED FLAME RETARDANCY AND DUST COLLECTING PROPERTIES.

United States Patent 3,695,926 Patented Oct. 3, 1972 3 695,926 FLAMERETARDAN DUST CONTROL FABRIC Alexander A. Scarborough, La Grange, Ga.,assignor to Deering Milliken Research Corporation, Spartanburg,

N'o'nmwin Filed Jan. 29, 1970, Ser. No. 6,972 Int. Cl. C09k 3/28, 3/22US. or. 117-136 7 Claims ABSTRACT OF THE DISCLOSURE Emulsifiable flameretarding compositions for preparing dust control fabrics are disclosed.The compositions comprise an oil having a flash point above about 150C., a flame retarding organic phosphate ester and emulsifying agent.These compositions readily form aqueous emulsions from which the oilcomposition is exhausted onto dust control fabrics such as cloths andmops. Such treated dust control fabrics exhibit improved flameretardancy and dust collecting properties.

BACKGROUND OF THE INVENTION This invention relates to emulsifiable flameretarding compositions, to processes for applying said compositions todust control fabrics, and to the fabrics so prepared.

Oil-treated or impregnated fabrics have been used extensively to removedust, dirt, and other powdery deposits from furniture, floors and walls.Such oily fabrics are utilized because of the dust-attracting propertiesof the oil which also serves to retain the dust until the fabric iswashed. One of the problems with such oil-treated or impregnated fabricsresults from the flammability characteristics of the oil itself.Oil-treated mops and dusting cloths present a fire hazard during storageor in use, especially when it is possible for these fabrics to come incontact with warm or burning objects such as cigarettes, or as a resultof heat generated through friction and static electricity. Such treatedfabrics also are capable of ignition through spontaneous combustion onstorage in areas where high temperatures are possible.

SUMMARY OF THE INVENTION These other problems associated with dustcontrol fabrics have been overcome by treating the dust control fabricswith an emulsifiable flame retarding composition comprising from about 1to 50 parts of an oil having a flash point above about 150 C., fromabout 20 to 80 parts of a flame retarding organic phosphate ester and upto about 20 parts of an emulsifying agent. These compositions may beapplied to the fabrics in any conventional manner such as by sprayingfrom an organic solvent or preferably by exhausting the composition intothe fabrics from an aqueous emulsion. The dust control fabrics preparedin this manner exhibit improved flame retardancy without loss of thedesirable attraction for dust particles. Particularly improved flameretardant and dust attracting properties are obtained when syntheticaliphatic polyester oils are utilized in the composition.

DESCRIPTION OF THE PREFERRED EMBODIMENTS This invention involvescompositions comprising an oil, an organic phosphate ester and anemulsifying agent. This oil composition is readily emulsified in waterby stirring. When dust control fabrics are contacted with the aqueousemulsion, the oil and organic phosphate ester are exhausted on thefabric from the emulsion.

The oils which are useful in the formulation of the flame retardantcompositions of the invention are those having a flash point above about150 C. The oils may be the readily available mineral oils, although oilsof animal, vegetable or synthetic origin are useful. Examples ofsynthetic oils which may be used are polyesters and polymerized olefinssuch as polyisobutene, polypropylene, polymerized cracked paraflinwaxes, etc. Although the mineral oils are used more often due to thecommercial and economical feasibility, the synthetic polyester oils andparticularly the synthetic aliphatic polyester oils are preferred sincethese provide the maximum flame retarding properties to the composition.Examples of such synthetic aliphatic oils include dioctyl adipate,dioctyl sebacate, dioctyl or didodecyl adipate and di-Z-ethyl hexylsebacate polymers obtained from the dibasic acid and the correspondingalcohols or glycols. Epoxidized soyabean oil is another example of asynthetic oil. Examples of synthetic aromatic esters are those lowmolecular weight polymers obtained from aromatic dibasic acids such asphthalic acid with alcohols and glycols such as butyl alcohol, hexylalcohol and ethylene glycol.

Mineral oils useful in the preparation in the composition of theinvention may be hydrocarbon oils having a viscosity value of from 50SUS (Saybolt Universal Seconds) at F. to 200 SUS at 210 F. Mixtures ofthe oils of different sources likewise are useful. Such mixtures areavailable from mineral oils (paraflinic or naphthenic), vegetable oils,animal oils, synthetic oils of the silicon type, synthetic oils of thepolyolefin type, synthetic oils of the polyester type, etc.

The organic phosphate esters useful in this invention are the triestersof phosphorus or phosphoric acid in which the ester radical is derivedfrom a substantially hydrocarbon radical including the aryl, alkyl,alkaryl, aryl-alkyl, or cycloal kyl radical as well as hydrocarbonradicals having polar substituents such as chloro, bromo, nitro, fluoroetc. Particularly desirable phosphates are those in which the esterradicals are phenyl, alkyl phenyl or alkyl radicals containing from 3 to8 carbon atoms. Examples of such phosphates include triphenyl phosphate,tricresyl phosphate, cresyl diphenyl phosphate, tris(1,3-dichloropropyl) phosphate, tris(2,3dichloropropyl) phosphate andtris(1-bromo3-chloro isopropyl) phosphate. These latter phosphate esterscontaining halogen appear to be most effective in improving the flameretardant properties of the composition, but the non-halogenatedphosphate esters provide adequate flame retardant protection at muchlower cost.

In addition to the oil and phosphate ester, the compositions of theinvention may contain up to about 20 parts of an emulsifying agent.Although the various types of emulsifying agents, namely, cationic,anionic and nonionic agents are effective to varying degrees, thecationic agents are particularly preferred for emulsifying thecompositions of this invention. The principal cationic agents are thequaternary amine salts wherein at least one of the substituents on thenitrogen is a long-chain alkyl group and the anion is either chloride orbromide. Examples of such cationic emulsifying agents include distearyldimethyl ammonium chloride, dicoco dimethyl ammonium chloride anddi-soya dimethyl ammonium chloride as well as the various n-alkyltrimethyl ammonium chlorides commercially available under the tradedesignation Arquad from Armour Industrial Chemical Company; landpolyethoxylated quaternary ammonium chlorides, also available fromArmour under the trade designation Ethoquad.

Other well known emulsifying agents such as the non ionic emulsifyingagents may be utilized although the above described cationic emulsifyingagents are preferred. Thus the emulsifying agent may be a mono-arylether of an aliphatic glycol. Specific examples include mono phenylether of ethylene glycol, mono-(heptylphenyl) ether of triethyleneglycol, mono-(alpha-octyl-betanaphthyl) ether of tetrapropylene glycol,mono-(polyisobutene (molecular weight of 1000)-substituted phenyl) etherof octapropylene glycol, and mono-,(o,p-dibutyl-phenyl) ether ofpolybutylene glycol, mono-(heptylphenyl) ether of trimethylene glycoland mono-(3,5-dioctylphenyl) ether of tetratrimethylene glycol, etc. Thealiphatic glycol may be a polyalkylene glycol. It is preferably one inwhich the alkylene radical is a lower alkylene radical having from 1 tocarbon atoms. Thus, the aliphatic glycol is illustrated by ethyleneglycol, trimethylene glycol, propylene glycol, 1,2-butylene glycol,2,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, or thelike. These mono-aryl ethers are obtained by the condensation of aphenolic compound such as an alkylated phenol or naphthyl with one ormore moles of an epoxide such as ethylene oxide, propylene oxide,trimethylene oxide, or 2,3-hexylene oxide. The condensation is promotedby a basic catalyst such as an alkali or alkaline earth metal hydroxide,alcoholate, or phenate. The temperature at which the condensation iscarried out may be varied within wide ranges such as from roomtemperature to about 250 C. Ordinarily it is preferably 50150 C. Morethan one mole of the epoxide may condense with the phenolic compound sothat the product may contain in its molecular structure one or more ofthe radicals derived from the epoxide. A polar-substituted alkyleneoxide such as epichlorohydrin or epibromohydrin likewise is useful toprepare the monoaryl ether product and such product likewise is usefulas the emulsion stabilizer in this invention.

Likewise useful as the emulsifying agents are the monoalkyl ethers ofthe aliphatic glycols in which the alkyl radical is, e.g., octyl, nonyl,dodecyl, behenyl, etc. The fatty acid esters of the mono-aryl ormono-alkyl ethers of aliphatic glycols also are useful. The fatty acidsinclude e.g., acetic acid, formic acid, butanoic acid, hexanoic acid,oleic acid, stearic acid, behenic acid, decanoic acid, isostearic acid,linolenic acid, as well as commercial acid mixtures such as are obtainedby the hydrolysis of tall oils, sperm oils, etc. Specific examples arethe oleate of mono- (heptylphenyl) ether of tetraethylene glycol andacetate of mono-(polypropene (having molecular weight of1000)-substituted phenyl)ether of tri-propylene glycol.

The alkali metal and ammonium salts of sulfonic acids likewise areemulsifying agents. The acids are illustrated by decylbenzene sulfonicacid, di-dodecylbenzene sulfonic acid, mahogany sulfonic acid,heptylbenzene sulfonic acid, polyisobutene sulfonic acid (molecularWeight 750), and decylnaphthalene sulfonic acid, and tri-decylbenzenesulfonic acid. The salts are illustrated by the sodium, potassium, orammonium salts of the above acids.

In addition to the oil, phosphate ester and emulsifying agent, thecomposition of this invention also may contain varying amounts ofsupplementary additives such as plasticizers, germicides, perfumes,coloring matter, etc. Known plasticizing compositions such as dioctylphthalate have been incorporated into the compositions in amounts up toabout parts. Smaller amounts of germicides may be incorporated, andexamples of these include various quaternary ammonium salts such asthose described above as being useful as emulsifiers and phenoliccompounds such as orthophenyl phenol.

As mentioned previously, the compositions of this invention wherein theoil is a synthetic aliphatic polyester oil, are preferred overcompositions containing mineral oil because of the improved flameretardant properties imparted to the dust control fabric when largeramounts of the composition are utilized. For example, when largeramounts of mineral oil containing compositions are applied to thefabrics to improve the dust pickup, the flame retardant propertiesdecrease. On the other hand, when similar amounts of the composition ofthis invention containing the synthetic aliphatic polyester oils areapplied to the same fabrics, the dust attracting and flame retardantproperties of the treated fabric are improved dramatically.

The fabrics which may be treated in accordance with the process of thisinvention include those fabrics customarily used for dust controlfabrics. These include fabrics comprised of cellulosic, keratinic andsynthetic fibers. Fabrics prepared from cellulosic fibers are most oftenused in the dust control industry and such fibers include cotton,cellulose acetate and regenerated cellulose such as viscose rayon.Suitable synthetic fibers which may be utilized either alone or incombination with the cellulosic fibers in the preparation of suitablesubstrate fabrics include synthetic polymeric fibers such as polyamides.(e.g., polyhexamethylene adipamide), acrylates (e.g.,polyacrylonitrile) and polyesters such as the various types ofpolyethylene terephthalate. Specially prepared flame retardant fibersalso may be utilized in prepared fabrics. An example of such fiber isknown as PFR Rayon available from American Viscose. Cotton mops treatedwith commercially available flame retardant chemicals such astetrakis-hydroxy methyl phosphonium hydroxide available from the HookerChemical Company or Pyrovatex CP .(a reactive phosphorus compoundavailable from Ciba) also constitute pre-treated fabric substrates whichcan be improved by this invention. Another well known treatment forimproving the flame retarding properties of the substrate fabric is atreatment with a combination of borax and boric acid in ratios of about2.5 to 1. About from 4 to 10% of the boraxzboric acid mixture is appliedto the fabric, based on the weight of the fabric to provide the desiredflame retardant properties. However, the fabrics treated with thesecompositions do not possess sufficient dust pickup properties to beacceptable for these applications. When the dust pickup characteristicsof the fabrics are improved by applying a dust-attracting oil to thefabrics, the improvement imparted by the flame retardant is diminishedby the presence of the flammable oils. This deficiency is overcome bythe composition of the present invention. When the compositions of theinvention are applied to fabrics which have been treated with thechemicals described above such as the boraxzboric acid composition,dramatically improved flame retardant and dust pickup properties areimparted to the fabric, and the amount of the composition applied to thefabric can be reduced to levels of about 5 to 15% based on the weight ofthe fabric.

The fabrics to be treated with the compositions of the inventions may bewoven, knitted, nonwoven, or stranded fabrics. In general, thecomposition of this invention may be applied to any fabric to improveits dust-attracting properties and its flame retardant characteristics.Such fabrics would include those used in the preparation of mops, dustcloths, dust tool covers, etc.

As mentioned previously, the compositions of this invention may beapplied to the fabric neat, in solution or as an emulsion. Emulsions orsolvents are preferred because of the ease of application. Aqueousemulsions may be prepared easily by adding the compositions of theinvention to water with stirring. The amount of water is not criticalalthough the time required for exhausting the composition into thesubstrate is proportional to the concentration of the composition in thewater. When exhausting this composition into the substrate, thesubstrate is merely placed into the emulsion and usually agitated untilthe desired amount of the composition is exhausted onto the fabric oruntil all of the composition is exhausted onto the fabric as isevidenced by the formation of a clear water Composition A:

Mineral oil having a flash point of about 213 C. and a viscosity of from54-74 cps. at

Parts 38 C. l Tris-dichloropropyl phospate 80 Di-soya dimethyl ammoniumchloride 1O Composition B:

Mineral oil as in Composition A Tricresyl phopshate 75 Di-stearyldimethyl ammonium chloride l5 Composition C:

Paraplex G-54 (a synthetic aliphatic polyester oil commerciallyavailable from Rohm and Haas Company) 8 Cresyl diphenyl phosphate 80Di-coco dimethyl ammonium chloride (available as Arquad 2C-75 fromArmour Chemical Co.) l0

Composition D:

Paraplex G-54 6.5

Houghto-Safe 1120 (an aryl phopshate ester available from E. S. Houghtonand C0.) 66.6

2-ethylhexyl diphenyl phosphate 13.4 The ammonium chloride ofComposition C 2.0 Emulsifier M85 (a cationic emulsifying agent availablefrom Northern Textile Chemical Company) 5.4

Composition E:

Paraplex G-20 (a sebacic acid-type polyester available from Rohm andHaas Company) l0 Tris (l-bromo-3-chloro isopropyl) phosphate 75 Arquad2C-75 5 Ortho phenyl phenol 1.5

Composition F:

Houghto-Safe 1120 40 Emulsifier M85 3 Arquad 2C-75 1 Paraplex G-54 4Cosmoline (Mineral oil with acid neutralizer available from E. S.Houghton & Co. under the designation RV) 0.5

Composition G:

Same as Composition F except that 21 parts of Paraplex G-54 is used inthe composition.

Composition H:

Similar to Composition F except that the Paraplex G-54 is replaced by anequivalent amount of dioctyl phthalate.

Composition I:

Similar to Composition F except that the Paraplex G-54 is replaced by anequivalent amount of mineral oil.

The improved flame retardant properties of the dust control fabricstreated with the compositions of this invention are shown by treatingone pound cotton stranded mops with emulsions of the compositionscontaining varying amounts of oil and thereafter measuring the flameretarding characteristics of the mops at different angles.

Several one pound cotton mops were placed in pails containing thecompositions identified as Compositions F through I diluted with waterto an approximate volume of two liters per mop. The mops were agitatedfor a period of about 3 to 6 minutes in the emulsion at room temperatureuntil the water became clear. The mops were removed from the pails,centrifugally spin dried and then tumble dried at an elevatedtemperature. The dried mops were then conditioned overnight in acontrolled atmosphere of a temperature of 70 F. and a relative humidityof 65% prior to being subjected to the following flammability tests.

In this flammability test, the mop fabrics are maintained in a certainposition and one end of the mop is ignited for 5 seconds whereupon thesource of the flame is removed. The time, distance of burning and anyafterglow is observed and recorded. Based on these observations, theflame retardant characteristics of the mops are indicated by rating themop on a scale of from 0 to 10, 0 indicating no flame retardingcharacteristics (complete burn) and 10 indicating no burn. The resultsof this test on mops maintained in four different positions, namely,horizontal, a 45 angle, a 75 angle and in the vertical position, aresummarized in the following table. The data indicate a dramatic andsignificant improvement in the flame retardant properties of the treatedmop fabrics. The dust-attracting properties of these mops are excellent.

TABLE-FLAME RETARDAN'I CHARACTERISTICS Trent- Ratings ment MopComposilevel Hori- 45 75 Vertisample tlon (percent) zontal angle anglecal Total Burns faster than untreated control.

It has been observed that the compositions of this invention wherein theoil is a synthetic linear polyester oil may be applied to fabrics athigh levels of add-on to increase the dust pickup properties withoutdrastic afl ect on the flame retardant properties of the fabrics. On theother hand, when mineral oils or synthetic aromatic polyester oils areused in the compositions, increased pickup results in a decrease in theflame retardant characteristics. For example, when Compositions F, H andI are exhausted on cotton mops as described above but to an add-on levelof 30%, the rating totals for the flammability test are 37, 14- and 18,respectively. These data demonstrate the clear superiority of thesynthetic aliphatic polyester oils in the compositions of the invention.

That which is claimed is:

1. A dust control fabric having incorporated therein a dust collectingoil composition consisting essentially of a liquid polyester oil havinga flash point above about 150 C. and a flame retarding organic phosphateester.

2. The fabric of claim 1 wherein the polyester is a synthetic aliphaticpolyester.

3. The fabric of claim 1 wherein the phosphate ester is a haloalkylphosphate ester having from 3 to 8 carbon atoms in the alkyl radical.

4. The fabric of claim 1 wherein the oil composition contains from about1 to 50 parts by weight of the polyester oil and from about 20 to partsby weight of the phosphate ester.

5. The fabric of claim 4 wherein the fabric contains from about 1 to 30percent by weight of the oil composition.

6. The fabric of claim 4 further having incorporated therein up to about15 parts by weight of the oil composition of a plasticizer.

7 7. The article of claim 1 wherein the fabric is a strand mop.

References Cited UNITED STATES PATENTS Cupery 55-524 Foehr 55-524 XCrocker et a1. 55-524 McGregory 15-10493 Smelling 15-10493 Herkimer55-524 X Slayter 55-524 8 Hanley 55-524 Hellman et a1. 117-1388 D X Woodet a1. 106-15 X Armstrong et a1. 55-524 WILLIAM D. MARTIN, PrimaryExaminer H. J. GWINNELL, Assistant Examiner US. Cl. X.R.

